[Bill Douglas]

Yep, it sounds like it's his bit of sewer before it reaches the Y intersection. So his problem ONLY.

I have the same thing in my old 116 year old house in Newtown. There is a legal bit in the property titles that says something like "The neighbor's poo has the right to travel along your property in the shared pipe" So no one can cut off the neigbour's sewage. Also around here we have the right to do "repairs" so it doesn't need to be torn up and brought completely to current specifications ie our own sewage pipes. I think the big cost is in making a new connection into the main sewer, the pipe itself is the easy bit.